Yet Another 2cyl steering thread

[Dale3887]

Well I might need to get up with rich sooner lol.

So got everything apart and measured all the components.

Part	Actual Measurement	Spec
ID Pump Body	2.086”	2.086-2.087”
Pump Body Width	varies .6274-.6278	.6270-.6280
Gear 1 OD	2.0805	2.0825-2.0835
Gear 2 OD	2.0805	2.0825-2.0835
Gear 1 Width	varies .6241-.6243	.6250-.6256
Gear 2 Width	varies .6246-.625	.6250-.6256
Body/Gear Clearance	.004	.002-.0024
Pump Shaft OD	varies .9930-.9980	.9994-1.000
Follower Shaft OD	.9975	1.053-1.063

The body/gear clearance I derived by subtracting the spec pump body width and gear width. I then laid the body back on the rear side of the pump and set the gears in it. Took a machinists ruler as a straightedge across the pump body and used feeler gauges to check the clearance. A 4 thousandths feeler just barely slides in the gap.

I did not measure the bushing IDs because they are brand new and
Have literally 20 minutes run time on them.
The follower shaft is the most surprising to me, but that’s the most square measurement I could get on it with my calipers.

So to my untrained eye, I need a pump shaft and follower shaft for sure. Which GPoVA can get me.

I think (and somebody correct me if I’m wrong) I should be hunting a set of gears if they can be found.

I suppose the other option would be having 2 thou machined off the pump body, but I’m skeptical that’s the right approach because I don’t know enough about gear pumps to know if that would help or hurt me.

The other thing of note is there are a couple of small dings and a score ring worn in to the rear pump face.

I’m attaching pictures of all the parts to this post.

I guess I’m wondering at what point am I throwing good money after bad and should hunt a reman pump, or is this one not actually too far gone, etc?

Rich I may give you a call tomorrow when I get freed up from work.


In the attached pictures gear 1 is on the left and the pump housing with the dowel pins still in it is the end of the pump that faces the engine (rear of the pump)

 

[LarrySTN]

So if I’m understanding your saying that having end play on the worm as the book says of 1-4 thou could potentially result in the worm and actuating sleeve assembly actuating the valve too far?

Just trying match up my understanding of how the system works with your comment. I understand the push/pull on the steering wheel part, as that could move the valve if there is too much end play in the work assembly.

It’s probably worth noting when I took it apart the bearings in the worm housing fell apart so I had to put new ones in when I reassembled it (those little bearing are stupid expensive from Deere) so bearing wear shouldn’t be a factor here which I have a feeling that’s what you’re compensating for when you preload the bearing rather than allowing end play.

My current plan is, knowing that I have a pump seal gone bad/leaking is to pull it back out. Strip it down again, check all the tolerances based on what the book says, which I didn’t do last time, I’m going to replace the seals, likely with some from green parts of va since they have the original style double lip wide seals. I believe they can get me a good pump shaft as well, so I’ll make a decision on that after I put the micrometer to it and find out just badly it’s worn.

Depending on tolerances I’ll go talk to my local hydro shop and see if they have a way to test the pump for me and/or have any suggestions for additional steps to take on rebuilding the pump/any machining to be done, etc.

If the tolerances are completely out of the realm of reality we’ll hunt either a good used pump or a reman pump.

Once that’s all done, we’ll get it back on the tractor, refill the oil and try it again. I’m hopeful it’s the seals were internally bypassing, due to installer error or some defect idk. I had one finger power steering the first two or three times I cycled the steering and then it slowly got worse. Since I couldn’t see any leaks that’s where I was assuming it was getting worse as it warmed up, but I’m hoping and thinking that it was actually just the seals starting to bypass internally more and more.

If we still have issues after we’ve validated and rebuilt the pump again, I’ll pull the known good valve off the 730 and stick it on this one and see if that fixes the issue.

I welcome any other input on my plan of attack though.

No it doesn't activate to far, it cause the valve to be moved in the wrong direction countering the normal direction of steering. Every unit that I've repaired, (fixed worn and broken parts) and then preloaded the tapered bearings has steered

So if I’m understanding your saying that having end play on the worm as the book says of 1-4 thou could potentially result in the worm and actuating sleeve assembly actuating the valve too far?

Just trying match up my understanding of how the system works with your comment. I understand the push/pull on the steering wheel part, as that could move the valve if there is too much end play in the work assembly.

It’s probably worth noting when I took it apart the bearings in the worm housing fell apart so I had to put new ones in when I reassembled it (those little bearing are stupid expensive from Deere) so bearing wear shouldn’t be a factor here which I have a feeling that’s what you’re compensating for when you preload the bearing rather than allowing end play.

My current plan is, knowing that I have a pump seal gone bad/leaking is to pull it back out. Strip it down again, check all the tolerances based on what the book says, which I didn’t do last time, I’m going to replace the seals, likely with some from green parts of va since they have the original style double lip wide seals. I believe they can get me a good pump shaft as well, so I’ll make a decision on that after I put the micrometer to it and find out just badly it’s worn.

Depending on tolerances I’ll go talk to my local hydro shop and see if they have a way to test the pump for me and/or have any suggestions for additional steps to take on rebuilding the pump/any machining to be done, etc.

If the tolerances are completely out of the realm of reality we’ll hunt either a good used pump or a reman pump.

Once that’s all done, we’ll get it back on the tractor, refill the oil and try it again. I’m hopeful it’s the seals were internally bypassing, due to installer error or some defect idk. I had one finger power steering the first two or three times I cycled the steering and then it slowly got worse. Since I couldn’t see any leaks that’s where I was assuming it was getting worse as it warmed up, but I’m hoping and thinking that it was actually just the seals starting to bypass internally more and more.

If we still have issues after we’ve validated and rebuilt the pump again, I’ll pull the known good valve off the 730 and stick it on this one and see if that fixes the issue.

I welcome any other input on my plan of attack though.

No, end play doesn't cause the valve to move too far but moves the valve to move in the opposite direction needed to cause power steering, causing it to bind. Why Deere ever recom me ended end play on tapered bearings is a mystery. All tapered bearings should have some preload to keep them from allowing the shaft run out of true. I tried numerous times to set up the power steering according to deere specs without ever being satisfied.....until I preloaded the tapered bearings. I have been very satisfied with this systems ever since. I had a deere mechanic tell me the deere power steerings never worked well and he preferred the behlen add on steering over the deere. I personally prefer the deere oem.

 

[Dale3887]

I had a nice 30ish minute chat with Richard this morning about the valve body, pump and worm setup. I think he’s got me on the right track.

For those following I will come back and post follow ups as I continue to make progress in hopes that this thread can eventually be a help to someone else in the future.

 

[620 John]

No it doesn't activate to far, it cause the valve to be moved in the wrong direction countering the normal direction of steering. Every unit that I've repaired, (fixed worn and broken parts) and then preloaded the tapered bearings has steered

No, end play doesn't cause the valve to move too far but moves the valve to move in the opposite direction needed to cause power steering, causing it to bind. Why Deere ever recom me ended end play on tapered bearings is a mystery. All tapered bearings should have some preload to keep them from allowing the shaft run out of true. I tried numerous times to set up the power steering according to deere specs without ever being satisfied.....until I preloaded the tapered bearings. I have been very satisfied with this systems ever since. I had a deere mechanic tell me the deere power steerings never worked well and he preferred the behlen add on steering over the deere. I personally prefer the deere oem.

I like the idea of having a slight preload on the bearings. I'll have to try that with my 620 some day.

I've wondered the same thing with JDs specs for tapered roller bearings. Some transmissions I work on set the shafts up with a preload and some with an end play.

After fighting the power steering on my 620 multiple times I finally found a worm gear and cams that were the updated style with the dowel pin and adjusting plug vs the old style with the adjusting screw. The later style actuator works much better. I can steer the tractor with one finger at a dead stop with a 6 row front mounted cultivator on. Can't spin the wheel like a 4020 but it's not bad.

 

[Dale3887]

I like the idea of having a slight preload on the bearings. I'll have to try that with my 620 some day.

I've wondered the same thing with JDs specs for tapered roller bearings. Some transmissions I work on set the shafts up with a preload and some with an end play.

After fighting the power steering on my 620 multiple times I finally found a worm gear and cams that were the updated style with the dowel pin and adjusting plug vs the old style with the adjusting screw. The later style actuator works much better. I can steer the tractor with one finger at a dead stop with a 6 row front mounted cultivator on. Can't spin the wheel like a 4020 but it's not bad.

It’s probably not far off the right track. I’ll probably butcher this but basically what Richard was telling me yesterday is that 4 thousandths endplay is likely excessive especially considering the wear present in the entire system.

I’ll post about my results once I get time to go through it again, but his suggestion to me was more or less yo close the manual and go by feel. Set the worm up with just the worm in the housing and it should just ever so slightly drag when you turn it by hand. Which if you measure it with an indicator is likely depending on wear a very slight preload to a thousandth of endplay. (Richard if I’m butchering what you told me yesterday I apologize) but basically leave the indicator in the toolbox and set it by feel was the jist of the advice he gave me.

 

[620 John]

It’s probably not far off the right track. I’ll probably butcher this but basically what Richard was telling me yesterday is that 4 thousandths endplay is likely excessive especially considering the wear present in the entire system.

I’ll post about my results once I get time to go through it again, but his suggestion to me was more or less yo close the manual and go by feel. Set the worm up with just the worm in the housing and it should just ever so slightly drag when you turn it by hand. Which if you measure it with an indicator is likely depending on wear a very slight preload to a thousandth of endplay. (Richard if I’m butchering what you told me yesterday I apologize) but basically leave the indicator in the toolbox and set it by feel was the jist of the advice he gave me.

It makes sense to me. With an end play at the tapered roller bearings it basically adds more slop to the actuator therefore "delaying" movement of the steering valve.

 

[420tlp]

Richard repaired my valve and 620 steers like a new tractor!

 

[EX Deere Farmer]

So I’ve been going through a saga with my 630. Seals completely gave out on the pedestal so I finally had to tear it apart. Got everything back together. Still didn’t have great steering so went ahead and did bushings, seals and bearings in the pump. This is where I’m at now. (Copy paste from my Facebook post)

Ok. Officially at a loss on the steering for this 630. Been through and rebuilt the pedestal (all seals including vanes, and bushings). Rebuilt the pump. All new seals bearings and bushings. Filled halfway up the dipstick with Deere steering oil (AF2235R). First start was encouraging, I had one finger power steering. The longer it sat here the worse the steering got to the point that it’s basically manual steering now. Gauge shows 400psi at full lock. Flow control adjustment makes 0 difference in pressure (book says it should go up to 130psi when adjusted right) neither backing it all the way out nor running it in as far as possible make any change in the pressure reading.

The valve is as centered as I can get it. Although that’s basically pushed as far back toward the operator as it can go within its bolt holes and I just barely have left hand steering.

I set all of the backlash adjustments as close as I was able with my dial indicator. Worm end play is right on 4 thou. Helix width is as close as I can get it to 2 thou. The only adjustment I didn’t make was taking shims out between the worm and pedestal. It had 3 7 thou shims in it, so I put 3 new ones back. The wheel has nearly a quarter turn of free play in it, which is the same as it was before. I assume taking a shim out would help that, but I don’t foresee it helping the hydraulic side of things.

When I put the pedestal back together I honed the lower bushing to 2.502” like the manual says. I didn’t hone the top bushing. Again like the manual says. The pedestal went back together hard, but I attribute that to new parts and tight bushing tolerances that should wear in over time.

I did add one shim to the steering sector gear as it measured 27thou and spec was max 21, adding one shim brought it down as near as I could measure it to between 10 and 11 thou so it’s right where it should be.

I can check the cold pressure tomorrow once things cool off just to see what pressure is cold.

But I’ve run out of ideas. I set everything as close to spec as I could via the manual, but it seems like I’ve done nothing but make the steering worse. (Not that it was good to begin with).

Manual steering seems ok, it’s tough but equal in both directions so i dont think theres bind in the pedestal or shafts. I think it’s more likely just the new parts that havent worn in. I could be wrong though.

What am I missing?

It still seems pump related to me. But I guess I could be wrong. There was some wear on the fan shaft but not enough that it’s leaking oil or sucking air now that the seals have been replaced. Am I possibly doomed to taking the pump back out and either getting a rebuilt unit or having this one machined?

My only other guess is my helix width is still wrong. I set my dial indicator up like the book suggested and tried to get a reading but since this tractor has the longer steering support arm it’s difficult to move the actuating sleeve at all. I’d welcome any and all advice (or videos) on adjusting the helix width

I would bet your problem is in the control valve. They get worn and leak internally. They then super heat the oil and the system quits working. It seems you oil is heating up pretty fast. I would go into the control valve.

 

[Dale3887]

Been a long busy summer but I finally have this tractor beat!

I sent the valve body off to Richard, he bored it out and replaced the spool with a new oversized spool.
Had to deal with some installer error while rebuilding the pump to fix a leak that the installer (Me) introduced after rebuilding it the first time. Finally got is all back together this week. Filled with Deere oil and it steers great. Not as good as the 720 I have that someone else rebuilt, but certainly good enough for a first crack at a full power steering rebuild. I think I need to revisit my worm end play and helix width again. But now that the tractor has one finger power steering I’ll have a much better chance of understanding the adjustments I’m making. But a short revisit on that and a few fine tweaks to the valve centering and it’ll be almost new again. I ran it today and drove it around just a bit, got it to almost operating temp, never lost steering once and when I checked the temps with my temp gun (after it had sat for 5-10 minutes and cooled some) around 100 degrees so I think the valve rebuild definitely solved the fast heating oil problem.

Wanted to say a big thank you to everyone who offered help in this thread. But the biggest thank you definitely goes to Richard Duane. I really don’t know that I would’ve been able to finish up this rebuild without his extremely helpful advice. Thank you again Richard!

I said earlier in this thread I would come back and post a conclusion for posterity’s sake. So here it is. The final answer to my problem was to have the steering valve rebuilt.